Variability of forwarder truckload parameters in the Pryazha forestry division of the Republic of Karelia (Russia): A computer experiment

Abstract The goal of the present research is to analyze parameters of a bundle of logs for various models of forwarders in the Pryazha division of forestry of the Republic of Karelia. The investigated parameters were mass and volume of a bundle of logs, stacking factor of the bundle and the number of wood assortments in the bundle. The following models of forwarders have been investigated: John Deere 1210E, John Deere 1110E, Ponsse Elk, Ponsse Wisent, Amkodor 2661-01, Rottne F13D, Rottne F15D, Rottne F18D. We estimated the parameters of bundles formed from spruce sawlog 6.1 m long and bundles formed from spruce pulpwood 4 m long. Data on stem forms from harvester recorders have been collected to assess the parameters of a bundle of logs. Parameters of bundles have been determined based on computer experiment. The experiment consists of the following steps: random selection of the stem from the database; simulation of the cut-to-length process; simulation of log stacking process; calculation of parameters of a bundle of logs. We found that parameters of bundles vary to a quite substantial extent. Average variability of a bundle of logs formed of 6.1 m long spruce sawlog is 4.5 t, variability of the volume is 5.8 m3, and variability of the number of wood assortments in a bundle is 49 pcs. For a bundle made up of 4 m long spruce pulpwood variability of mass is on average 2.8 t, that of volume – 2.09 m3, that of the number of wood assortments – 57 pc. The presented results can inform transportation of wood on cutting areas, planning timber harvesting, as well as development new logging machines.